George j



UNITED STATES PATENT OFFICE.

GEORGE J. COVERT, 0F WAYNE, .AND BYRON A. SHAW, OF BRADFORD, NEW,YOR.

GRINDINGr-PLATE FOR FEED-MILLS.

Specification of Letters Patent.

Patented June 10, 1919.

Application mea .Tune 29, 1917. serial No. 177,739.

invention is to provide a plate` of this class Y,

which will grind all kinds of grain, etc., more thoroughly and quickly and with the use of less power than other plates now in use.

Another object of the invention is to provide a plate having grinding teeth converging inwardly from the rim of the plate and grinding and deflecting ribs projecting from said teeth in a direction to form acute angles with said grinding teeth and substantially parallel with the rim of the plate.

Another feature of the invention is the provision of broad-faced teeth and ribs capable of withstanding a great amount of roughY usage4 and exceptionally long-lived, the device being fully effective even after stones, nails and other refractory objects have passed between the plate and a complemen- V tary plate with which it coacts. Our plate is also self-sharpening, and because of the broad faces before mentioned will do perfect work even when the teeth and ribs have been worn down until nearly iiush with the face of the plate itself.

Another important feature relates to the arrangement of the ribs nearest the rim on the converging main teeth, the peripheral rib on one side of each tooth cooperating with the outermost rib on the tooth nearest thereto in the direction of rotation, this outer rib being a deiiecting rib and lying at some distance from the periphery7 of the plate and being adapted to shunt the partly ground materialv into the acute angular pocket formed by the first-mentioned peripheral rib and its tooth.

Theseand other objects ,of the invention will be described herein and claimed, and are illustrated in the accompanying drawing, which shows a face view of our improved grinding plate.

Referring to the drawing, 2 designates generally the grinding plate of our invention. This plate is adapted for coperation with a complementary plate, one of these being rotative and the other xed, and each is (lished at 3 in the ordinary manner to form wlth its complementary plate a feed intake for the grain deliyered by the conveyer from the hopper of the mill in whichvthe plates are used. This mill and its conveying means may be any adapted for feeding grain, etc., to the plates, one of which is adapted for fixture to a rotary head and the other of which is fixed. The fixed and movable plates will, preferably, be of similar construction. At 4 we have shown broad-faced gathering teeth extending from the rim of the plate inwardly to the extreme inner edge of said plate. Teethv 5, `preferably regularly spaced between the teeth 4,' and of the same general type, extend inwardly in the same general direction as the teeth 4, but are stopped at the beginning of the dished portion 3 of the plate, thisarrangement facilitating the even distribution of the grain to the different grinding portions of the plate. Springing from each of the teeth 4 and 5 are deiiecting grinding ribs 6 preferably of the same broadfaced type as the teeth themselves. These `ribs in the preferred construction are at an acute angle to their respective teeth and are substantially parallel with the rim of the plate. At 7 are shown deflecting ribs formed on vthe side of each tooth opposite the grinding ribs 6. t

At the outer end of each of the teeth 4 and 5 is a peripheral grinding rib 8 of such length as to allow a portion of the face of the plate at the rim beyond the extremity of said grinding rib to forman ej ecting space 9 for the completely ground material. These peripheral ribs also are of the same broadfaced type as the teeth'and ribs before described and each lies at a slightly acute angle to its tooth on the grinding side thereof. In coperation with each peripheral rib 8 and its tooth is an opposite rib 10 parallel with the rib ,8 and springing from the adjacent tooth ata point inside the periphery and at such a distance from ,the rib 8 as toy provide the most effective positioning for effecting a divertingof the partially ground material to the' pocket 11 formed by the main tooth and its peripheral rib. Here the shearing action is so pronounced thatthe material is at' thispoint reduced to a most evenly ground mass before it passes away from the shearing pocket and is ejected at the rim of the plate, the openings 9 facilitating this ejection.

While a characteristic feature of the plate of our invention is the broad-faced grinding teeth and ribs, with the ribs at an acute angle to the teeth, the ribs on the deiiecting or back side of each tooth may be at other angles to their respective teeth, but in all cases the teeth on the forward or shearing side will be at an angle slightly acute to the teeth from which they spring.

At 12 we have shown the usual bolt-holes for permitting' the plate to be fastened to the rotary 'head of a mill for copcration with a complementary fixed plate, which lixed plate may be of the same type as the rotary plate.

In the operation of a mill provided with the grinding plate here shown, the grain or other material to be ground passes from a hopper of any ordinary construction through a suitable conveyer and is brought to the intake formed by the dishing of the two plates, from which it is, by centrifugal force, carried toward the rim of the plates. 0n its way toward said rim it is subjected to a very thorough and rapid grinding, being also repeatedly delieeted to bring it again and again into the shearing angles formed by the grinding teeth and their grinding ribs. The positioning of the ribs in the construction of the invention brings -about an oft repeated and very violent diversion or deflection of the material at all stages of its progress, the diverting grinders 6 and 7, because of their positioning with respect to their teeth andthe teeth and ribs of the coacting plate, contributing to produce a thoroughness and evenness of grinding with the expenditure of a small amount of power.

It has been found in practice that the most thorough grinding is eected by the provision of diverters 10 for cooperation with the outer portion of the grinding teeth and ribs when the material has been reduced to approximately the desired fineness and evenness. These diverters serve to defleet the material around into the pockets formed at 11, where it is subjected to the Vpowerful shearing action of the acuteangled portion of the grinding face immediately within the rim of the plate, after which it passes out, thoroughly and evenly ground, at the rim of the plate. There will of course be means on the mill for adjusting the removable plate with respect to the fixed plate, such means being any ordinarily employed for this purpose. The plates, moreover, may be of any desired diameter of face to lit mills of various sizes for use with light or more powerful engines, and the teeth and ribs may be of different lengths and surface areas.

The grinding plate described herein, although of simple construction and having no delicate parts to be injured, is capable of grinding a greater quantity of wet or dry grain, and grinding it more evenly in 'a given time with a given expenditure of power than any of the grinding plates now used for the same purpose.

Because of the 'broad faces of the grinding teeth and ribs a plate of this description may be used by inexpert and even careless operators without fear of injury to the plate, for it will not be appreciably damaged by the passage through the mill of foreign matter, such as stones, nails, etc., often found in farm grain taken directly from the separator and given no additional cleaning. It is for this special farm use that the plate herein described has been developed', and for this purpose it has proven extremely durable, long-lived and effective.

What we claim is:

1. An annular grinding plate for feed mills, embodying main grinding teeth `converging inwardly from the rim of said plate and whose inner ends are tangent to a line concentric with said rim, and a plurality of grinding ribs on each of said teeth having inner and outer edges substantially parallel with said rim.

2. An annular grinding plate for feed mills, embodying main grinding teeth converging inwardly from the rim of said plate, and whose inner ends are tangent to a line concentric with said rim, an intermediate shorter grinding tooth between each pair of main teeth, a plurality of grinding ribs on said main and intermediate teet'h having inner and outer edges substantially parallel with said rim, and discharge openings at said rim between each pair of grinding` teeth.

3. An annular grinding plate for feed mills, embodying main grinding 'teeth converging inwardly from the rim of said plate and whose inner ends are tangent to a line concentric with said rim, an intermediate shorter grinding tooth between each pair of main teeth, a plurality of grinding ribs on said main and intermediate teeth having inner and outer edgesfsubstantially parallel with said rim, deflecting ribs on the opposite side of said main and intermediate teeth from said grinding ribs and also substantially parallel with said rim, and discharge openings at said rim between each of said main teeth and its opposite intermediate tooth.

4. An annular grinding plate for feed mills, embodying main grinding teeth converging inwardly from therim of said plate and whose inner ends are tangent to a line concentric with said rim, an intermediate shorter grinding tooth between each pair of main teeth, a plurality of grinding ribs on said main and intermediate teeth having inner and outer edges substantially parallel with said rim, deleeting ribs on the opposite side of said main and intermediate teeth from said grinding ribs and also substantially parallel with said rim, the outerinost of said deflecting ribs on each tooth lying inside the riJn of the plate, and dis- V charge openings at the rim adjacent to each of said outermost defleeting ribs.

5. An annular grinding plate for feed mills, embodying main grinding teeth converging inwardly from the rim of the plate, intermediate teeth between said main teeth, the inner ends of said main and intermediate teeth being tangent to a line concentric with said rim, grinding ribs on said main and intermediate teeth having their inner and outer edges parallel with the rim, a peripheral grinding rib on each of Said main and intermediate teeth and forming at its junction with said tooth an acuteangled pocket for detaining and grinding the material delivered thereto, and a discharge opening at the rim beside each peripheral rib.

Signed at Bradford, in the county of Steuben, and State of New York, this 19th day of June, A. D. 1917.

GEORGE J. COV ERT. BYRON A. SHAW. Witnesses:

WM. R. BARKLEY, EDGAR SANFORD.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

